Sweet cherries belong to the rose family (Rosaceae) and are a stone fruit. They originated from wild cherries and are subdivided into heart and white-heart cherries. Heart cherries have soft flesh and are therefore not so prone to bursting. They are, however, less transportable than firm-fleshed white-heart cherries, which, in contrast, have the disadvantage of a greater susceptibility to bursting.

Sweet cherries come in several shades: yellow, bright (light) and dark (reddish to black). Heart cherries are generally dark in color, while white-heart cherries are frequently bright-colored. Inside, cherries have a hard stone enclosing the seed and the stone is itself surrounded by fleshy pulp.

Sweet cherries are harvested from the trees, which vary markedly in height, only when fully ripe, since they are not amenable to post-ripening. If cherries are picked too early, they are no longer able to develop their typical characteristics and spoil very rapidly.

Quality / Duration of storage

The quality of sweet cherries is determined by uniform color and size depending on the variety. They must not be overripe or display any injury caused by birds, rot or hail. They should also be examined for green mold They must not be picked in the rain and must be picked with the stem on. It is recommended that fitness for loading be confirmed by an inspector.

The storage life of sweet cherries is very restricted due to their delicate skin. Because they spoil easily, they should be sold as soon as possible after harvesting. Only firm-fleshed white-heart cherries are suitable for transport over relatively long distances (10 days maximum, [1]).

Where controlled atmosphere transport is used, transport and storage duration may be extended. The following parameters apply in such a case [16]:

Temperature

Rel. humidity

O2

CO2

Suitability for controlled atmosphere

1.1 - 2.2°C

90 - 95%

10 - 20%

20 - 25%

good

Intended use

The sweet cherry is the original dessert cherry, but, apart from being eaten fresh, it is also used in the preparation of jams and preserves, stewed fruit, drinks, ice cream and confectionery.

Figures

(Click on the individual Figures to enlarge them.)

Figure 1

Figure 2

Countries of origin

This Table shows only a selection of the most important countries of origin and should not be thought of as exhaustive.

Cherries have delicate skin and must therefore be treated with appropriate care during cargo handling, since injury to the fruit skin results in rapid spoilage. The cold chain must at all costs be maintained, since otherwise there is a risk of rapid spoilage.

In damp weather (rain, snow), the cargo must be protected from moisture, as there is otherwise a risk of premature spoilage.

Because of its considerable impact- and pressure-sensitivity, packages of this cargo must be secured in such a way that they are prevented from damaging each other. Spaces between packages or pallets must be filled, to prevent slippage or tipping. By selecting the correct packaging size or cargo unit (area module or area module multiple), holds can be tightly loaded (without spaces).

They are living organs in which respiration processes predominate, because their supply of new nutrients has been cut off by separation from the parent plant.

Care of the cargo during the voyage must be aimed at controlling respiration processes (release of CO2, water vapor, ethylene and heat) in such a way that the cargo is at the desired stage of ripeness on reaching its destination. Inadequate ventilation may result in fermentation and rotting of the cargo as a result of increased CO2 levels and inadequate supply of atmospheric oxygen (see Ventilation).

Although cherries do not suffer damage at a CO2 content of 4 vol.%, the content should be kept at 0.5 vol.% with regard to a necessary and adequate supply of fresh air.

Ethylene evolution

Active behavior

The rate of ethylene production is very low, being below 0.1 µl/kg*h [16].

Passive behavior

Ethylene sensitivity may be classified as low [16]. To prevent premature spoilage, however, they must not be stored together with apples, pears and citrus fruit (allelopathy).

If ventilation has been inadequate (frost) or has failed owing to a defect, life-threatening CO2 concentrations or O2 shortages may arise. Therefore, before anybody enters the hold, it must be ventilated and a gas measurement carried out.

If ventilation has been inadequate (frost) or has failed owing to a defect, life-threatening CO2 concentrations or O2 shortages may arise. Therefore, before anybody enters the hold, it must be ventilated and a gas measurement carried out.

This disease causes the most damage to cherries. It is caused by various molds and its initial symptom is a small, circular, slightly sunken brown rot spot. Beneath this spot, the pulp is very moist and light brown. As the disease progresses, white and subsequently blue-green mold deposits form, before the fruit rots completely.

Gray mold rot:

This occurs very frequently in cherries during storage and develops particularly well at temperatures between 18 and 24°C.

Brown rot:

Brown rot is caused by molds of the genus Monilia. It can be recognized by typical concentric rings on the surface of the fruit.

Cherry fruit fly:

Attack by the cherry fruit fly maggot (Rhagoletis cerasi) is manifested externally by a brown, sunken area near the stem-end. It destroys the pulp around the stone and turns it into a brown, rotting mass.

Another problem from which cherries suffer is bursting: cherries absorb water when it rains, causing the skin to burst. Burst cherries are extremely susceptible to rot and are therefore no longer salable.

The quarantine regulations of the country of destination must be complied with and a phytosanitary certificate may have to be enclosed with the shipping documents. Information may be obtained from the phytosanitary authorities of the countries concerned.